Fastener driving device



April 26, 19 60 H. w. MARANO 2,934,039

FASTENER omvmc DEVICE Filed Nov. 5, 1956 2 Sheets-Sheet 1 ATTORNEY 2 Sheets-Sheet 2 Filed Nov. 5, 1956 m m R M O 6 m w 5 E T w m 6 I a 3 6/ m T y ,w/ m M n I? n n 6 w 7 {I T 1. 2 w w n 1/ /,0 .n :d 7 a 7 4 0 6 n h. J a 7 s .w 7% a: 7/ x m )v a 3W 9 4 5 Q 5 M W di BY (0121M! {m ATTORNEY Uited tates Patent FASTENER nRIvtNG DEVICE Herbert W. Marano, Summit, NJL, assignor to Wilson Jones Company, Chicago, 11]., a corporation of Massachusetts Application November 5, 1956, Serial No. 620,277

11 Claims. (Cl. 121-13) The present invention relates generally to an improved driving device, and it relates more particularly to an imprincipally to the structure of the cylinder and piston system, the air distributing system and the properties of the components employed.

It is therefore a principal object of the present invention to provide an improved driving device.

Another object of the present invention is to provide an improved pneumatically driven staple gun.

Still another object of the present invention is to provide an improved pneumatically driven staple gun of simple, rugged and inexpensive construction.

A further object of the present invention is to provide an improved pneumatically driven staple gun of rapid action and high efiiciency.

Still a further object of the present invention is to provide an improved pneumatically driven staple gun in which the drivestroke is accompanied by a minimum of shock.

The above and other objects of the present invention will become apparent from a reading of the following description, taken in conjunction with the accompanying drawing, wherein Figure 1 is an exploded perspective view of a pneumatic staple driving gun embodying the present invention;

Figure 2 is a vertical, longitudinal, sectional view thereof, the staple magazine being illustrated in closed position;

Figure 3 is a view similar to Figure 2 shown partially broken away with the magazine end in open position;

Figure 4 is a sectional view taken along line 44 in Figure 2;

Figure 5 is a sectional view taken along line 5-5 in Figure 2; and

Figure 6 is a sectional view taken along line 6-6 in Figure 3.

In a sense, the present invention contemplates the provision of an improved pneumatic device comprising a cylinder having upper and lower ports formed therein, a piston disposed in said cylinder and movable between upper and lower positions, a drive member engageable by said piston, first conduit means communicating with said upper port, second conduit means communicating with said lower port, third conduit means adapted to communicate with a gas under pressure and valve means for selectively alternatively connecting said first and second conduit means or said first and third conduit means.

Another feature of the present invention resides in the structural arrangement of the various parts of the device which comprises a body portion including a pair of vertically spaced rearwardly directed parallel legs con nected at their forward portion by a vertical cross arm, said cross arm having formed therein a forwardly directed vertically extending recess terminating at its upper portion with a downwardly directed well, a cylinder mem- I 2,934,039 Patented Apr. 26, 1960 ice her registering with said recess and having an upper end nesting in said well and a bottom wall provided with a vertically extending aperture, a piston disposed in said cylinder and a drive member engaging said piston and extending through said aperture, said body portionhaving a bore formed therein having an inlet and an outlet communicating with the upper portion of the interior of said cylinder.

A further feature of the present invention is the provision of a bumper formed of nylon which absorbs the shock of the driving ram and exhibits an unexpected superiority to bumpers formed of other materials.

Reference is now made to the drawing which illustrates a preferred embodiment of the present invention and wherein the numeral 10 generally designates the body of the driving device which includes a suitably shaped upper horizontal handle portion 12, a lower vertically spaced base portion 14, the forward ends of the handle portion and base portions 12 and 14 being connected by a vertical cross arm 16. l The vertical cross arm 16 has formed in its forward face a vertically extending recess 18 of arcuate cross section, the forward edges 20 of which are inclined forwardly and upwardly to a point 22 which is located in the forward rim of a downwardly directed well 24 of circular transverse cross section. Formed in the handle portion 12 is an upper horizontal bore 26 which extends from a vertical valve cavity 28 of circular cross section to the trailing end of the handle portion 12 terminating in an internally threaded section 30 to permit the coupling of a high pressure air hose. The lower portion of the valve cavity 28 communicates by way of a bore 32' to an upwardly extending groove 34 formed in the base of the recess 18. The groove 34 communicates with a forwardly extending horizontal groove 36 formed in the basevof the well 24 to approximately the center of the base. A lower horizontally extending passageway 38 extends forwardly from the lower end of the valve cavity 28 to a downwardly extending groove 40 formed in the base of the recess 18 to apoint above the lower end thereof, the passageway 38 being separated from the bore 32 by an intervening wall 42. The upper portion of the valve cavity 28 is threaded as at 44 and is provided at its upper end with an enlarged portion 46. The lower end of the cavity 28 isof reduced circular cross'section to provide an annular shoulder '50.

Located in the valve cavity 28 is an upper valve casing 52 having an upper enlarged portion 54 provided with a forwardly directed circular port 56 and an upper edge defining a valve seat. Depending from the upper casing portion 54 is a lower casing portion 58 of reduced cross section having formed in its upper section a forwardly directed port 60. Slidably located within the valve cavity 28 and the valve casing 52 is a valve member 64 includ ing an upper head portion 65 provided with an upstanding internally threaded tubular member 66 and a depending stem 67 which terminates in a cylindrical portion 68 of enlarged cross section. An annular valve gasket member 69 and a superimposed annular cap 70 register with the tubular portion 66 and are secured in position by a suitable screw 71 which engages the tapped bore of the tubular member 66. In assembled condition the cylindrical portion 68 slidably engages the vertical bore of the depending valve casing portion 58 and the underface of the gasket 69 is movable between a closed position wherein the gasket 69 rests upon the upper edge of the valve casing which defines the valve seat and a position above the valve seat to effectthe opening of the valve. The lower valve cylindrical portion 68 is so disposed and movable within the valve casing 58 that when the valve is in closed position, as illustrated in Figure 2 of the drawing, the port 60 is open and when the valve is raised to its fully open position the port 60 is closed by 'vided a finger piece or trigger 74 having a pair of horivlzontally spaced upstanding forward lugs 76 with aligned openings 77 formed therein, the lugs 76engagrng rearwardly directed ear 78 located in the upper inner corner to permit the swinging of the trigger 74 which is in its lowermost position when the valve is closed.

-A tubular member 80 defining a cylinder nests in the body member recess 18, and in the well 24, the upper edge'of the tubular member .80 abutting the base of the well 24. An opening 81 is formed in the wall of the cylinder 80 and communicates with the lower end of the groove 40, the upper end of the cylinder 80 communicating with the groove 36. A cap ,membert82 is provided with an upstanding externally threaded annular 83 and a base portion 84 of greater diameter than the ring 83 to provide an outwardly directed shoulder 86, the threaded ring 83 engaging a corresponding thread formed in the lower inner face of the cylinder 80, the

shoulder 86' tightly abutting the lower edge of the cylinder 80. The base 84 has a vertical transverse diametrically extending slot 87 formed thereinand a pairofvertically extending circular ports 88 disposed forward of the slot 87. Depending from the underface of the base .84 is ,a rectangular block 89, the front face-of which is 'invertical coplanar alignment with the rear edge of the .slot 87. 'The block 89 has a longitudinally extending f the body member 10. VA pin 79 engages the openings "77 and the corresponding opening formed in the ear 78 medial recess formed therein and a transverse bore 90 jThe body base portion 14 isof channel-shaped cross section and has disposed therein an inverted channelshaped member 91 having a pair of laterally spaced rearicommunica'ting with said recess and at right angles thereto.

wardly vdirected fingers 92 and a second pair of forwardly directed laterally spaced fingers 94, the fingers 92 having aligned openings 96 formed at their trailing ends and the fingers 94 having a pair of aligned openings97 formed at their leading ends. A longitudinally extending bar 98 is substantially coextensive with the channel-shaped member 91 and is provided with upper rear longitudinally extending recess 100 and forward longitudinally extending recess 101 provided with .a lower step portion 192, the purposes of the recesses being hereinaftcr .Set forth. A plurality of tapped vertical bores 103 are formed .in the bar'98 and are in alignment withcorresponding openings 104 and 106 formed in the U-shaped member 9.1 and in the body member base portion 14 respectively. Headed screws 107 pass through the corresponding openings 106 and 104 and engaging the respective. tapped bores 103 to efiect the securement of the bar 98. and the provided with openings aligned with the openings-90, 108

and 97, the components 110, 82, 98 and 91 being interconnected by the tubular screw pair 112 passing through corresponding openings formed in these components.

The cross arm of the U-shaped member is provided with a forwardly stepped vertically extending portion 1115, the rear face of which is vertically v coplanar with the'forward face of the slot 87 formed in the cap '82.

Slidably located in the cylinder 80 is a hollow cup- I shaped piston 113 having a top wall 114 and a depending .116. A piston follower 117 is nested within the piston 113 and is provided with anupper enlarged head .of laterally aligned openings.

. 4 V 118 which bears against the underface of the piston top wall 114. Depending from the head 118 is a shank 119 of reduced cross section terminating in a depending yoke portion 120. A staple drive blade 121 is of rectangular cross section having its upper end engaging the piston follower yoke portion and being secured thereto by means of a pin 122 passing through corresponding openings formed in the upper end of the drive blade 121 and in the arms defining the yoke 120. The driving blade 121 slidably engages the slot 87 formed in the cap 82, the lower edge of the drive blade 121 being located slightly above the lower forward edge of the cap block 89 when the piston 113, follower117, and driving blade 121 are in their uppermost position as illustrated in Figures 2 and 3 of the drawing.

A pair of bumper elements 123 and 125 respectively are each formed of nylon and are disposed within the cylinder 80 at the lower end thereof. The bumper 123 has a'base portion which nests within the.collar.83 and is provided with an upstanding portion 126 of smaller transverse cross section than the base to delineate an annular shoulder 127. A vertical slot 128 is formed in the bumper 123 and slidably engages the drive blade 121 and is in vertical alignment with the slot 87 formed in the cap 82. Also formed in the bumper 123 are two pair of vertically extending bores 129 a forward pair of which are in alignment with the bores 88 formed in the cap member 82 and the rear pair of bores communicating with the forward bores by means of channels 130 formed in the underface. of the bumper 123. The bumper 125 is collar-shaped and is likewise formed of nylon and rests upon the, upper face of the cap ring 83. Formed in the rear top wall of the bumper 125 is a recess 131 which registers with the opening 81 formed in the wall of the cylinder 80 to provide free access between the channel 40 and the interior of the cylinder. A helical compression spring .132 encircles the drive'blade 121 and is entrapped between the bumper shoulder '127 and the undcrf ace of the piston follower head 118 to normally urge the assembled follower and drive blade117 and 121 and the piston 113 to their topmost position.

The staple gun magazine includes a channel-shaped base portion 136 having upstanding sides 137, the upper edges of which are of a configuration conjugate to the lower edge of the corresponding side walls of the body member base 14. The rear of the base side walls 137 have upwardly projecting lugs 138 provided with a pair A hollow internally threaded bolt 139 provided with a lock screw 140 passes through the openings in the lugs 138, an opening formed in the rear of the bar 98, the openings 96 and openings 141 formed in the lower ends of a pair of laterally spaced bars 142. The upper ends of the bars 142 likewise have openings formed therein which are engaged 'by a pin 143 carrying a spacer 144 located between the ends of the bars 142, the pin' in turn being carried by the lower free end of the body portion handle .12 and registering with a recess 146 formed therein. It is thus apparent that the channel-shaped base member 137 and the entire assembly carried thereby is swingable about the bolt 139 toward and away from the body member base portion 14.

A staple guide 150 is located within the magazine base 136 and is of inverted channel shape having depending .sides 151' each of which is provided with a longitudinally extending recess 152 along its bottom edge terminating at the rear portion thereof with an upwardly forwardly in- ..clined recess 15.3. Forward and rear fingers 154 and andhas a leg 158 thereof provided with a projecting portion which engages a slot 159 formed in the bar 98 and ,legs160 which engage corresponding holes formedrin the lower rear corners of the staple guide side walls 151 urging the magazine toward an open position.

The forward edge of the staple guide 151 is vertically aligned and coplanar with the rear edge of the slot 87 formed in the cap member base portion 83 and is also in alignment and coplanar with the front face of a tongue 161 which depends from the forward edge of the bottom wall of the magazine base 136. A nose piece 163 includes a front wall 164 having rearwardly directed upper lugs 165 which engage the magazine base sides 137 and which are secured thereto by suitable rivets. The upper edge of the nose piece 163 registers with the lower edge of the wall 115 when the magazine is in closed position. It should be noted that the confronting spaced faces of the tongue 161 and the leading edge of the staple guide 151 and the nose piece 163, define a staple throat or exit channel as well as a passageway for the lower end of the drive blade 121 during the drive stroke and the confronting faces of the wall 115 and the cap block 89 as well as the slot 37 and the bumper slot 128 form aguide for the drive blade 121.

A saddle-shaped staple pusher member 166 straddles the staple guide 151 and is locked in sliding engagement with the staple guide 151 by means of a plate 167 which registers with a pair of aligned horizontal slots. 168 formed in the depending side walls 169 of the staple pusher 166. The plate 167 bears against the longitudinal edges of the guide recesses 152 and is provided with laterally projecting apertured rear lugs 178. Carried on the inner faces of the magazine base side walls 137 adjacent the forward end thereof are a pair of laterally spaced pulleys 171 which are rotatably supported by suitable rivets 172 which pass through corresponding openings formed in the wall 137. A pair of helical tension springs 173 extend around the pulleys 171 and have forward hooked ends 174 engaging the apertures formed in the pusher lock plate lugs 1'78 and have hooked rear ends 176 engaging inwardly extending hookshaped ears 177 formed in the rear portion of the magazine base side walls 137. Thus, the pusher 166 is spring urged towards a forward position.

In order to lock the magazine in closed position, there is provided a latching element 178 in the form of a fiat rectangular frame which slidably engages an upstanding portion 179 of the bar 98 and has front and rear legs slidably registering with the recesses located adjacent the opposite ends of the upstanding portion 179. The forward end of the latching member 178 is provided with laterally extending ears 185 which slidably register with slots 180 formed in the channel-shaped member 91 and slots 181 which are formed in the forward edge of upstanding portions 182 located at the forward part of the magazine base side walls 137. A pin 183 passes through an opening 184 formed in the bar 98 to retain the latching member 178 upon the bar 98. Urging the latching member 178 to its rear locked position are a pair of helical springs 186, the forward ends of which engage openings 187 formed in the latching member 178 and the rear ends of which engage a pair of lugs 188 depending from the upper wall of the member 91.

A latch manipulating member 189 consists of a pair of laterally spaced parallel longitudinally extending walls 190 which slidably embrace the side faces of the bar 98 and which are connected by upper forward and rear bridge portions 191 which ride in the slots 100 and 101 formed in the bar 98. A finger piece 192 projects upwardly from the rear of the manipulating member 189 through the recess 193 formed in the upper wall of the body member base portion 14. The forward edge of the pusher 189 engages the rearward end of the latch member 178. In locked position the latch member 178 is in its rearmost location, the ears 185 engaging the magazine base slots 181 to lock the magazine in closed position. By pushing the locking member 189 forward by way of the finger piece 192 the latching member 178 is moved located in the staple throat into the work piece.

forwardly out of engagement with the magazine base recesses 181 permitting the spring 157 to swing the magazine into open position. To close the magazine it is merely swung upwardly, the cam edges of the upstanding portions 182 forcing the latching member 178 forwardly which then is urged rearwardly by the springs 186 into engagement with the recesses 181.

In operation, the improved staple gun is loaded by retracting the pusher 166 to its rearrnost position wherein it registers with the recess 153 and is retained therein. A stack of staples is placed on the guide 150 and the magazine is swung into closed position, the pusher 166 being urged downwardly by the pressure of the lower edge of the bar 98 upon the forward upper edge of the pusher 166 and out of engagement with the recess 153 and is pulled forwardly by the springs 173 to urge the forwardmost staple of the stack into registry with the staple throat. The magazine is then locked in position as previously described.

A source of compressed air is connected to the gun by means of a suitable hose coupled to the threaded end 30 of the bore 26. The lower end of the staple throat is then positioned upon the work piece and the valve opened by finger pressure upon the trigger element 74. In opening the valve the port 60 is closed by the valve member 68. It should be noted that in actuating the valve the pressure of the air must be overcome so that a predetermined finger pressure must be employed. However, as soon as the valve is cracked the required force is reduced and the valve opens rapidly. The upper access to the valve communicates with the bore 26 thereby permitting compressed air to travel by way of the bore 26, valve cavity 28, valve port 56, bore 32, and channels 34 and 36 to the upper end of the cylinder to expose the upper face of the piston 116 to the high pressure air. The piston is thus rapidly depressed driving the follower 117 and the drive blade 121 through its stroke to drive the staple The majority of the air located in the lower portion of the cylinder is discharged through the openings 88 and 129 formed in the cylinder cap 82 and bumper 123. Upon reaching its lower position the bottom of the piston skirt 116 and the bottom of the follower 119 strike the upper portions of the bumpers 125-and 123'respective so as to absorb any impact. It has been discovered that by reason of the bumpers being formed of nylon the shock is minimized and the bumpers are of indefinite life. It should be noted that when the follower is in its lowermost position the openings to the bores 88 and 129 are sealed by the underface thereof and the spring 132 is under full compression. However, the interior of the piston 113 communicates with the channel 40 by way of the openings 131 and 81 formed in the bumper 125 and cylinder respectively. Upon release of the trigger 74 the valve is rapidly returned to its lowermost closed position sealing the source of compressed air from the valve 52 and opening the valve port 60. The compressed air in the upper portion of the cylinder 80 travels along the various channels and bores through the valve 52 and valve port 60 to the underface of the piston 113 to assist and speed up the return of the latter to its upper position. As the openings to the bores 88 are uncovered by the follower 117 the air under pressure within the lower portion of the cylinder 80 may discharge through the aforesaid bores. It has been found that by reason of the above construction of the cylinder, piston and valve arrangement a much more rapid return stroke is realized and the need for a heavy return spring is obviated. The result is a more efficient driving device of improved characteristics.

While there has been described and illustrated a preferred embodiment of the present invention, it is apparent that numerous alterations and omissions may be made without departing from the spirit thereof.

I claim:

1. A pneumatic driving device comprising a cylinder having upper and lower ports formed therein, a :piston disposed in said cylinder and movable between upper and lower positions, a drive member engageable by said piston, first conduit means communicating with said upper port,

second conduit means communicating with said lower port, third conduit means adapted to communicate with a gas under pressure and valve means for selectively alternatively connecting said first and second conduit means, and said first and third conduit means.

2. A pneumatic driving device in accordance with'claim 1, wherein the upper and lower faces of said piston are exposed to said upper and lower ports when said piston is in its respective upper and lower positions.

3. A pneumatic driving device in accordance with claim 1, including spring means urging said piston to its upper position.

4. A pneumatic driving device in accordance with claim 1, wherein said cylinder is provided with a bottom wall having exhaust ports formed therein and including means movable with said piston and adapted to seal said exhaust ports when said piston is in its lowermost position.

5. A pneumatic driving device in accordance with claim 4, including a cushion member located atthe lower end of said cylinder and having openings formed therein registering with said exhaust port and a passageway .slidably engaging saiddrive member.

6. .A pneumatic driving device in accordance withclaim .4, including a nylon cushion member located at the lower and the lower portion of said cylinder to urgesaid piston follower to bear against the underface or said piston.

8. A pneumatic driving device in accordance with claim 1, wherein said valve normally elfects communication between said first and second conduit means and including finger manipulated means for actuating said valve toefiect communication between said first and third conduit means.

9. A driving'device comprising a base member having a first guide aperture formed therein, a reciprocable driving member registering with said first guide aperture, a ram disposed above said base member and engaging said driving'rnember and movable therewith, means for imparting 'a driving stroke to said ram and said driving member and a nylon bumper located between said ram configuration as said first guide aperture, the driving member sealing the guide apertures in the base and in the bumper at the end of the driving stroke. 7

10. A pneumatic driving device comprising a longitudinally extending cylinder having a bottom and a top wall, said bottom wall having exhaust ports formed therein, a piston member located in said cylinder and longitudinally slidable therein between said top and bottom walls and having a downwardly directed underface, a nylon bumper disposed on said bottom wall and having vertically extending bores'formed therein and registering with exhaust ports, the *underface of the piston sealing the bores whenthe piston bears against the nylon bumper.

11. A pneumatic driving device comprising a longitudinally extending cylinder having a bottom and a top wall, a piston located in said cylinder and longitudinally slidable therein between said top and bottom wall, said piston having a top wall and a depending peripheral skirt, a follower registering with said piston and bearing against .the underface of the top wall thereof, a first annular shaped nylon bumper located on said bottom wall and confronting the lower edge of said piston skirt, and a second nylon bumper concentric with said bumper and confronting the underface of said follower, and wherein said cylinder bottom wall and said second bumper have aligned exhaust openings formed therein, the underface of said follower sealing said exhaust openings when said follower is in its lowermost position.

References (lited in the file of this patent UNITED STATES PATENTS 

